Lath



ct. 17, 1939. G. A. BuTTREss LATH g Mam/fw Buff/ess;

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Filed April 20. 1937 Patented Oct. 17, 1939 UNITED STATES PATENT OFFICE6 Claims.

This invention relatesto ribbed lath and more particularly pertains toimprovements in ribbed boards of the character set forth in UnitedStates Letters Patent Number 2,077,513 issued to me April 20, 1937.

An object of the invention is to provide a ribbed lath embodying hollowribs in which the spaces within the ribs are enclosed to form dead airspaces within the lath.

A particular object of the present invention is to provide a lath of theabove character in which the ribs of the lath are reinforced by sheetmetal housed interiorally of the'lath ribs, and in which the metalreinforcements are so formed that they may be readily positioned withinthe ribs and -held in place therein.

With the foregoing objects in view together -with such other objects andadvantages as may lsubsequently appear the invention is carried intoeffect las illustrated by way of example in the yaccompanying drawing inwhich:

Fig.r1fis a perspective View of a fragmentary po-rtion of the ribbedlatch panel with portions broken away:

Fig. 2 is a detail in vertical section of the lath panel particularlyshowing the manner of forming the reinforced hollow ribs thereof:

l Fig. 3 is a perspective View of the sheet metal reinforcement:

Referring to the drawing more specifically A indicates a backing sheetwhich may be formed of any; suitable material such as paper, pulp boardand the like, but which is preferably flexible. In some instances thebacking sheet may consist of or may embody thin sheet metal. Where fireproofing is desired the sheet A may be formed of asbestos or other fireresistant fibrous material.

Mounted on the backing sheet A is a corrugated facing sheet B offlexible material, the corrugations of which are dove tailed in crosssection toy form the sheet with a series of parallel hollow ribs 5 withadjacent ribs spaced apart and with dove tailed grooves or channelsextending therebetween. The facing sheet B is preferably formed of atleast two plies 'l and 8 of paper or similar sheet material, betweenwhich is interposed a moisture resistant layer 9 with which the sheets'l and 8 are adhered together. The sheet B is affixed to the backingsheet A in any suitable fashion such as by an adhesive.

An important feature of the present invention resides in the provisionof reinforcing strips C arranged within the ribs 5 which strips areformed of lengths of sheet metal having a transvers-e widthsubstantially corresponding to the (Cl. l2-116) width of the inner facesof the ribs 5 and which sheets are formed with inturned marginal flangesI which are inclined inwardly relative to each other and'seat ony theinner faces of the inclined si-de walls Il of the ribs 5. the flanges l0are spaced from the backing sheet A so as to impart a stiffening actiononly along the outer marginal portions of the side walls of the ribs andnot interfere with the flexibility of the inner marginal portions of theside walls of the f ribs, and whereby the walls of the channels betweenthe ribs are capable of being flexed from their juncture with thebacking sheet to a point intermediate their inner and outer margins thusThe inner margins of .p

rendering the sheet lath quite flexible throughout Avl5 except acrossthe outer faces of the ribs, and greatly minimizing possibility ofrupture of the lath at the juncture of the bottom walls of the channelsand the side walls of the ribs. As a means for imparting longitudinalrigidity to the reinforcing strip it is formed with a series oflongitudinally extending corrugations l2 which are spaced from thebacking sheet so as to permit free flexing of the latter inwardly towardthe reinforcing strip throughout the width of the portions of thebacking sheet extending across the bases of the ribs and whereby thesheet lath may be readily rolled into a compact bundle and also appliedto the inside sharply curved supporting structures as in forming coves.The reinforcing s trips C are preferably formed of lengths correspondingto the lengths or' the sheets B, and are arranged within the ribs withtheir ends extending ush with the end margins of the ribs and held inplace by an adhesive. However the strips C are further held in placeagainst the ribs by reason of being formed of a width to conform to thewidth of the inner surfaces of the-outer walls of the ribs and with theinwardly inclined flanges I0 seating in the acute angle formed at thejuncture of the outer walls of the ribs and the side walls thereof.

In order to facilitate nailing of the lath board to a supportingstructure the sheets B are formed with nail receiving apertures I4adjacent the ends thereof, which slots pass through the reinforcingstrip C` as indicated in Fig. 3 and through which the shanks of nailsmay be readily passed, thus avoiding driving of nails through the metalreinforcing strip. However the strip being formed of thin sheet metal issubject to penetration by nails and accordingly nails may be driventhrough the sheets B and reinforcing strip C where occasion so requires;the slots I4-l5 being particularly serviceable where the margins ofadjacent panels are overlapped so as to minimize the necessity ofdriving nails through two overlying thicknesses of the sheet metalstrips.

The operation of the invention is obvious since it is apparent that theribbed sheets may be applied in the usual fashion as by nailing to asuitable backing structure in the manner common to applying ribbedboards. On being so applied the ribbed surface is plastered in the usualmanner.

By the provision of the sheet metal reinforcing strip C collapsing ofthe ribs C in applying the plaster is prevented and furthermore metalties are afforded throughout the lathed surfaces thus imparting strengthto the walls covered by the lath.

The flanges l0 are shown made sufficiently narrow to confine them to theouter halves of the spaces within the ribs, but the width of saidflanges may be greater so long as they do not eX- tend so close tothebacking sheet asto excessively impair the flexibility of the walls lll.

While I have shown and described a `s-pecic embodiment of the inventionI do not limit myself to the exact details of construction shown, andthe invention accordingly embodies such changes and modifications ascome Within the purview of the appended claims.

I claim:

1. A hollow ribbed lath comprising a backing sheet, a facing sheetcarried by said backing sheet, said facing sheet being formed with aseries of spaced hollow ribs, said ribs and the grooves betweencontiguous ribs being of dovetail cross section, and metallicreinforcing strips arranged interiorally of said ribs, said reinforcingstrips bearing against the inner faces of said ribs throughout andhaving longitudinal flanges bearing against the sides of said ribs withthe margins of said flanges spaced from said backing sheet, said angesbeing confined to the outer halves of the spaces within said ribs.

2. A hollow ribbed lath comprising a backing sheet, a facing sheetcarried by said backing sheet, said facing sheet being formed with aseries of spaced hollow ribs, said ribs and the grooves between the sidewalls of contiguous ribs being of dove-tail cross section, and metallicreinforcing strips arranged interiorally of said ribs, said reinforcingstrips bearing against the inner faces of said ribs and havinglongitudinal flanges bearing against .only the outer portions of thesides of said ribs; said strips being formed with longitudinallyextending corrugations; the margins of said flanges and the walls ofsaid corrugations being spaced a substantial distance from said backingsheet to permit flexion of the portions of said side Walls which arefree from said flanges.

3. A hollow ribbed lath comprising a backing sheet, a facing sheetcarried on said backing sheet, said facing sheet being formed with aseries of Iparallel hollow ribs which have side Wall portions, and asheet metal reinforcing strip extending interiorally of each of saidribs abutting against the inner surfaces of said ribs and adheredthereto and being spaced from said backing sheet a substantial distanceto permit material flexion of parts of said Wall portions.

4. A hollow ribbed lath comprising a backing sheet, a facing sheetcarried on said backing sheet, said facing sheet being formed with aseries of parallel hollow ribs having side walls, and a sheet metalreinforcing strip extending interiorally of said ribs abutting againstthe inner surfaces of said ribs; said reinforcing strip being spaced asubstantial distance from said backing sheet throughout.

5. A hollow ribbed lath comprising a backing sheet formed of reresistant fibrous material, a facing sheet carried on said backingsheet, said facing sheet being formed with a series of parallel hollowribs having side wall portions, and a sheet metal reinforcing stripextending interiorally of said ribs abutting against the inner surfacesof said ribs and spaced a substantial distance from said backing sheetthroughout, thereby leaving strips of said side wall portions free toflex to a material extent.

6. A hollow ribbed lath comprising a backing sheet, a facing sheetcarried on said backing sheet, said facing sheet being formed with aseries of -parallel hollow ribs having flexible side wall portions, anda sheet metal reinforcing strip extending interiorally of said ribsabutting against the inner surfaces of said ribs and spaced asubstantial distance from said backing sheet throughout to permitflexing of a material part of said side wall portions; said backingsheet being formed of fire resistant fibrous material and said facingsheet being formed of fibrous material having limited moistureabsorptiveness.

GEORGE A. BUTIRESS.

